When Hui returned to Hong Kong after her stay in London, she became the assistant to the prominent Chinese film director, King Hu. Her breakthrough directorial work began with several drama series and short documentaries on 16mm for the Television Broadcasts Limited (TVB) television station. During 1977, Hui produced and directed half a dozen films for the Independent Commission Against Corruption (ICAC), a Hong Kong organization created to clean up government misconduct. Two of these films were so controversial that they had to be banned from airing. A year later, Hui directed three episodes Below the Lion Rock, which depicts the lives of people from Hong Kong, under the public broadcasting station, Radio Television Hong Kong (RTHK). The most recognized episode of Hui’s is Boy from Vietnam (1978), which is the start of her "Vietnam trilogy."[3]

After a few years in the television industry, Hui finally directed her first feature-length film, The Secret (1979). In the 1980s, Hui’s career was growing on the international cinema circuit. The most popular films for that time were Eastern variations of Hollywood oriented gangster and action films. But Hui did not follow the trend and preferred to create more personal films. Many of her best films involved themes pertaining to cultural displacement. In particular, her central characters are often individuals who are forced to relocate to another country and shown to be struggling and learning to survive. Hui tends to explore the characters' reactions to different environments and their responses to their return home. Her best known works, which fall under this category, are The Story of Woo Viet (1981) and Boat People (1982) – the remaining two parts of her "Vietnam trilogy." Although Hui has directed some generic films, another common theme she works with is family conflict, such as in the film My American Grandson (1990).

One of her most personal work is Song of the Exile (1990), a semi-autobiographical film. The film depicts the story of a young woman, Cheung Hueyin returning to Hong Kong for her sisters wedding after studying film in London for a couple of years. The Hueyin and her mother, who is Japanese, do not seem to have a steady relationship. But as the film follows Hueyin’s journey to her mother’s hometown in Japan, Hueyin and her mother are forced to reexamine each other’s relationship, as both have experienced the issue of being uprooted from one’s own country.

In the 1990s, Hui’s work began to target more commercialized films. Her directing career has slowed down a bit, as she focused more on behind-the-scenes work for other filmmakers. However, the theme of displacement is still recurrent in most of her works. During the mid-1990s, Hui tried to start up a film project about the Tiananmen Square massacre and the reactions of Hong Kong citizens. But the project was never made due to the lack of investments and funding. The term Tiananmen Square massacre is no longer in use by the Chinese government, as it portrays a harsher image of the incident. It is now more recognized as the Tiananmen Square protests or the June Fourth Incident. Throughout her career, Hui has often taken chances to develop more intense and ambitious films, while making a name for herself.[4]

Hui has said in an interview about her desire to work on more socially conscious projects. She was aware of the difficulties in finding such projects that would both "attract investors as well as appeal to the public." Her goal was to "present something that is watchable and at the same time attractive" and allow the public to analyze the social issues involved. Although Hui is best known for making controversial films, the interview, in particular, was describing the horrors of increased crime and unemployment rates in Tin Shui Wai, Hong Kong. The two films of Hui’s that focus on these issues are The Way We Are (2008) and Night and Fog (2009), while maintaining a motif of displacement.[5]

Hui left television in 1979, making her first feature The Secret, a mystery thriller based on real life murder case and starring Taiwanese star Sylvia Chang. It was immediately hailed as an important film in the Hong Kong New Wave. The Spooky Bunch (1981) was her take on the ghost story genre, while The Story of Woo Viet (1981) continued her Vietnamese trilogy. Hui experimented with special effects and daring angles; her preoccupation with sensitive political and social issues is a recurrent feature in most of her subsequent films. Boat People (1982), the third part of her Vietnamese trilogy, is the most famous of her early films. It examines the plight of the Vietnamese after the Vietnam War.[6]

In the mid-1980s Hui continued her string of critically acclaimed works. Love in a Fallen City (1984) was based on a novella by Eileen Chang, and the two-part, ambitious wuxia adaptation of Louis Cha's first novel, The Book and the Sword, was divided into The Romance of Book and Sword (1987) and Princess Fragrance (1987). 1990 saw one of her most important works to date, the semi-autobiographical The Song of Exile. The film looks into the loss of identity, disorientation and despair faced by an exiled mother and a daughter faced with clashes in culture and historicity. As in the film, Hui's own mother was Japanese.

After a brief hiatus in which she returned briefly to television production, Hui returned with Summer Snow (1995), about a middle-aged woman trying to cope with everyday family problems and an Alzheimer-inflicted father-in-law. In 1996, she was a member of the jury at the 46th Berlin International Film Festival.[7]

In 2008, Hui directed the highly acclaimed domestic drama, The Way We Are, which was then followed up by Night and Fog. In an interview with Muse Magazine, Hui explains how she sees the two films as about something uniquely Hong Kong: '(on Night and Fog) I think that this film can represent something; it can express a kind of feeling about the middle and lower class, and maybe even Hong Kong as a whole. Everyone can eat at McDonald's or shop at malls. That's a way of life, but spiritually, there's dissatisfaction, especially with families on welfare. They don't really have any worries about life, but there's an unspeakable feeling of depression.'[8]

A Simple Life (2011) is Hui's most recent film to date. The film centers around the relationship of two characters, Ah Tao (Deanie Ip) and Roger (Andy Lau). It is not a love story, but rather a tale about a master and his long-time servant.

Starring Chow Yun-fat, the film is Hui's second part to her "Vietnam trilogy," which follows the story of a South Vietnamese refugee in Hong Kong. This film was one of first political Hong Kong-made dramas. It was screened at the Director's Fortnight of the Cannes Film Festival.

The third installment of Hui's "Vietnam trilogy." Andy Lau plays one of several Vietnam refugees, who are forced to flee to Hong Kong. The film was an Official Selection at Cannes and Best Film at the Hong Kong Film Awards

An elderly Chinese man becomes the caretaker of his 12-year-old grandson. The film compares the differences of Eastern and Western culture, and analyzes how American born Chinese disassociates themselves their native culture.

A comedy-drama about a working woman and her husband and son. The woman must care for her father-in-law, whom she had never gotten along with. The film centers around the woman's situation and how she copes with her father-in-laws Alzheimer's. The film has received several awards.

The melodrama about a stunt woman (Michelle Yeoh), who is struggling in Hong Kong's film industry. The film is most famous for Yeoh's brush with death, as she misjudged an 18-foot leap from a bridge to a truck.

The film follows the story of a high school teacher with a good life and family. However, the film shows the deterioration of relationships and marriages when a young student falls in love with the teacher.

The film is an adaptation of a popular book that describes the lives of everyday police men. The protagonist is a female police officer, who must deal with choices between three men in her life and her career.

A woman in her sixties discovers she is falling behind in the times, as she loses her job as an English tutor. Throughout the film, several people (including her own nephew) take advantage of her naiveté, which leaves her penniless.

This drama tells the story of a working woman, Kwai, who must take care of her teenage son and ailing mother. Kwai befriends an older woman, and the two learn to help each other during a time where employment is scarce and any kind of assistance is highly appreciated.

A family struggles in Tin Shui Wai, while marriage between husband and wife turns fatal. There is no social, physical, or emotional escape for the wife, who is an immigrant to Hong Kong, of an abusive husband.

A story about an elderly female servant, who has watched over a family for many generations. Andy Lau is the only family member left in Hong Kong, and the film follows the relationship between servant and master.